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Monographs of fragrance chemicals and extracts that have caused contact allergy / allergic contact dermatitis
Published in Anton C. de Groot, Monographs in Contact Allergy, 2021
p-Cymene is a colorless to pale yellow clear liquid; its odor type is terpenic and its odor at 1% in dipropylene glycol is described as ‘fresh citrus terpene woody spice’ (www.thegoodscentscompany.com). p-Cymene is used to improve the odor of soaps, detergents and sanitation goods and as a masking odor for industrial products. It also acts as the starting material for the production of p-cresol, carvacrol and acetyl hexamethyl tetralin. Other uses include or have included as a solvent for dyes, varnishes and lacquers, as heat-transfer fluid, in metal polishes and in the manufacture of synthetic resins (U.S. National Library of Medicine).
Chemistry of Essential Oils
Published in K. Hüsnü Can Başer, Gerhard Buchbauer, Handbook of Essential Oils, 2020
Myrcene (70) is very widespread in nature. Some sources, such as hops, contain high levels and it is found in most of the common herbs and spices. All isomers of α-ocimene (84), β-ocimene (85), and allo-ocimene (86) are found in essential oils, the isomers of β-ocimene (85) being the most frequently encountered. Limonene (73) is present in many essential oils, but the major occurrence is in the citrus oils that contain levels up to 90%. These oils contain the dextrorotatory (R)-enantiomer, and its antipode is much less common. Both α-phellandrene (87) and β-phellandrene (88) occur widely in essential oils. For example, (−)-α-phellandrene is found in Eucalyptus dives and (S)-(−)-b-phellandrene in the lodgepole pine, Pinus contorta. p-Cymene (83) has been identified in many essential oils and plant extracts and thyme and oregano oils are particularly rich in it. α-Pinene (65), β-pinene (76), and 3-carene (77) are all major constituents of turpentine from a wide range of pines, spruces, and firs. The pinenes are often found in other oils, 3-carene less so. Like the pinenes, camphene (89) is widespread in nature.
Pharmacokinetics behaviors of l-menthol after inhalation and intravenous injection in rats and its inhibition effects on CYP450 enzymes in rat liver microsomes
Published in Xenobiotica, 2019
Xiuli Feng, Yan Liu, Xiao Sun, Ang Li, Xiaoyan Jiang, Xiaosong Zhu, Zhongxi Zhao
Phenacetin, testosterone, dextromethorphan, omeprazole, tolbutamide, chlorzoxazone, β-NADP and β-NADPH were purchased from Sigma-Aldrich Chimie (Saint Quentin Fallavier, France). l-Menthol (purity >98%) was bought from Melun Biotechnology Co., Ltd. (Dalian, China). P-cymene (purity >95%) was obtained from Tokey Chemical Industry Co., Ltd. (Tokyo, Japan). Formic acid and tris(hydroxymethyl)aminomethane (Tris) were purchased from Beijing Chemical Reagents Company (Dongdan, Beijing, China). Rat liver microsomes were bought from Ruide Research Institute for Liver Disease Co. Ltd (Shanghai, China). HPLC-grade acetonitrile was purchased from Tedia Company (Fairfield, OH). All liquids used for the experiments were filtered through 0.22-μm membrane filters from Millipore (MA). Ultrapure helium (purity of 99.999%) was purchased from Jinan Deyang Special Gases Co., Ltd (Jinan, China).
Metabolism and pharmacokinetics studies of allyl methyl disulfide in rats
Published in Xenobiotica, 2019
Yan Liu, Ang Li, Xiaoyan Jiang, Xiaosong Zhu, Xiuli Feng, Xiao Sun, Zhongxi Zhao
P-cymene was adopted as the internal standard for the determination based on our preliminary and published studies (Germain et al., 2002; R. Artacho Martin-lagos MFOSMDRL, 1995). AMDS (1 μl) was added to 199 μl of rat erythrocytes and incubated for 5 min at 37 °C. After incubation, 400 μl of acetonitrile which contained p-cymene as an internal standard at the concentration of 37.5 μg/ml were added to the incubation mixture in order to terminate the reaction. Next, the mixture was vortexed for 10 min and then centrifuged at 12 000g for 10 min. Finally, after filtered through a 0.22 μm microporous membrane, 1 μl of the supernatant was injected into GC–MS for the identification of the metabolites of AMDS in the incubation mixture with rat erythrocytes.
Phytochemical constitutes and biological activities of essential oil extracted from irradiated caraway seeds (Carum carvi L.)
Published in International Journal of Radiation Biology, 2023
Amina Aly, Rabab Maraei, Ahmed Rezk, Ayman Diab
The high ability to free radical scavenging can also be attributed to the presence of an excessive rank of Carvone, because it contains a conjugated double bond and therefore, has excessive antioxidant properties. Furthermore, Carvone has been confirmed as a defensive substance against lipid peroxidation. Also, P-cymene as a monoterpene has excessive antioxidant properties during the interactions with other monoterpenes, resulting in synergistic interactions that partially explain the strong antioxidant effect of the EOs (Hajlaoui et al. 2021). Additionally, modifications in molecular conformation as an effect of irradiation therapy may be linked to the rise in total phenols concentration (Kumari et al. 2009).